Springboot+Mybatis + 异源数据库（Oracle&Mysql）

1.背景

最近的项目需要同步另外一个数据库的数据，因此开始捣鼓springboot双（多）数据库的配置。参考了很多博客和手册，顺便整理了自己的项目，成功运行并。

2.思路

专门画个图，方便理解

3.按图走起，follow me

3.1 pom.xml添加一些依赖

<!-- oracle依赖 -->
<dependency>
    <groupId>com.oracle</groupId>
    <artifactId>ojdbc6</artifactId>
    <version>11.2.0</version>
</dependency>
<!-- Mysql依赖 -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- 数据池依赖 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.0.18</version>
</dependency>      

3.2 application.properties配置两个数据源

server.port=8080



master.datasource.url=jdbc:oracle:thin:@//233.233.233.233:1521/xjyj
master.datasource.username=数据库用户名
master.datasource.password=数据库密码
master.datasource.driverClassName=oracle.jdbc.driver.OracleDriver


second.datasource.url=jdbc:mysql://localhost:3306/hoava?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true
second.datasource.username=数据库用户名
second.datasource.password=数据库密码
second.datasource.driverClassName=com.mysql.cj.jdbc.Driver      

3.3 数据源的配置

注意：多数据源配置的时候，数据源应该有主次之分，需要有一个主数据源，我们配置MasterDataSourceConfig为主数据源

MasterDataSourceConfig.java

1.@Primary表示这个Bean如果有多个同类Bean候选时，优先考虑。（多数据源配置必须有主数据源，用@Primary表示该Bean）

2.@MapperScan 扫描 Mapper 接口并容器管理，包路径精确到 master（一定注意精确到的包路径，否则出现binding exception）

3.@Value 获取全局配置文件 application.properties 的 kv 配置,并自动装配。sqlSessionFactoryRef 表示定义了 key ，表示一个唯一 SqlSessionFactory 实例

@Configuration //配置注解
@MapperScan(basePackages = MasterDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {
    static final String PACKAGE = "com.dock.dao.master";
    static final String MAPPER_LOCATION = "classpath:mapper/master/*.xml";
    @Value("${master.datasource.url}")
    private String url;

    @Value("${master.datasource.username}")
    private String user;

    @Value("${master.datasource.password}")
    private String password;

    @Value("${master.datasource.driverClassName}")
    private String driverClass;

    @Bean(name = "masterDataSource")
    @Primary
    public DataSource masterDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        return dataSource;
    }

    @Bean(name = "masterTransactionManager")
    @Primary
    public DataSourceTransactionManager masterTransactionManager() {
        return new DataSourceTransactionManager(masterDataSource());
    }

    @Bean(name = "masterSqlSessionFactory")
    @Primary
    public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(masterDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(MasterDataSourceConfig.MAPPER_LOCATION));
        return sessionFactory.getObject();
    }
}      

SecondDataSourceConfig.java

@Configuration
@MapperScan(basePackages = SecondDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "secondSqlSessionFactory")
public class SecondDataSourceConfig {
    static final String PACKAGE = "com.dock.dao.second";
    static final String MAPPER_LOCATION = "classpath:mapper/second/*.xml";
    @Value("${second.datasource.url}")
    private String url;

    @Value("${second.datasource.username}")
    private String user;

    @Value("${second.datasource.password}")
    private String password;

    @Value("${second.datasource.driverClassName}")
    private String driverClass;

    @Bean(name = "secondDataSource")
    public DataSource clusterDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        return dataSource;
    }

    @Bean(name = "secondTransactionManager")
    public DataSourceTransactionManager clusterTransactionManager() {
        return new DataSourceTransactionManager(clusterDataSource());
    }

    @Bean(name = "secondSqlSessionFactory")
    public SqlSessionFactory clusterSqlSessionFactory(@Qualifier("secondDataSource") DataSource clusterDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(clusterDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(SecondDataSourceConfig.MAPPER_LOCATION));
        return sessionFactory.getObject();
    }
}      

4.走正常流程：

4.1service层

@Service
public class TestServiceImpl implements TestService {

    @Autowired
    private TestDao testDao;

    @Autowired
    private TestDaoTwo testDaoTwo;

    @Override
    public List testCon() {
        List<v_t_xk_by_yjskc> list = testDao.testCon();
        System.out.println("============第一个数据库");
        System.out.println(list);
        List list1 = testDaoTwo.testDaoTwo();
        System.out.println("============第二个数据库");
        System.out.println(list1);

        List listall  = new ArrayList();
        listall.add(list);
        listall.add(list1);
        return listall;
    }

}      

4.2dao层

目录结构如图

TesDao

@Repository
@Mapper
public interface TestDao {
    List testCon();
}      

TesDaoTwo      

@Repository
@Mapper
public interface TestDaoTwo {
    List testDaoTwo();
}      

4.3   Mapper

4.4 Controller

@Controller
@RequestMapping(value = "/test")
public class testController {
    @Autowired
    private TestService testService;

    @ResponseBody
    @RequestMapping("/te1")
    public Map<String, Object> testCon1(){
        Map<String,Object> result = new HashMap<>();
        result.put("two",testService.testCon());
        return result;
    }

}      

4.5启动入口配置

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class}) //去除默认datasource配置
@ServletComponentScan
public class DockApplication extends SpringBootServletInitializer {

    public static void main(String[] args) {
        SpringApplication.run(DockApplication.class, args);
    }
}      

5.最终结果如图：

目录结构如图